conv(3C)

NAME

conv: toupper(), tolower(), _toupper(), _tolower(), toascii() — translate characters to uppercase, lowercase, or 7-bit ASCII

SYNOPSIS

#include <ctype.h>

int toupper(int c);

int tolower(int c);

int _toupper(int c);

int _tolower(int c);

int toascii(int c);

DESCRIPTION

toupper() and tolower() have as domain the range of getc(3S): the integers from -1 through 255. If the argument of toupper() represents a lowercase letter, the result is the corresponding uppercase letter. If the argument of tolower() represents an uppercase letter, the result is the corresponding lowercase letter. All other arguments in the domain are returned unchanged. Arguments outside the domain cause undefined results.

The macros _toupper() and _tolower() are identical to toupper() and tolower(), respectively.

toascii() yields its argument with all bits that are not part of a standard 7-bit ASCII character cleared; it is intended for compatibility with other systems.

EXTERNAL INFLUENCES

Environment Variables

LC_CTYPE determines the translations to be done.

International Code Set Support

Single-byte character code sets are supported.

WARNINGS

toascii() is supplied both as a library function and as a macro defined in the <ctype.h> header. To obtain the library function, either use a #undef to remove the macro definition or, if compiling in ANSI C mode, enclose the function name in parenthesis or take its address. The following examples use the library function for toascii():

#include <ctype.h> 
#undef toascii 

main() 
{ 
     ...
     c1 = toascii(c); 
     ...
} 

#include <ctype.h> 

main() 
{ 
     int (*conv_func)(); 
     ...
     c1 = (toascii)(c); 
     ...
     conv_func = toascii; 
     ...
} 

The following example use the library function for toupper():

#include <ctype.h> 
#undef toupper 

main() 
{ 
     ...
     char *c; 
     *c=toupper ((unsigned char*) c); 
     ...
} 

AUTHOR

conv() was developed by IBM, OSF, and HP.

STANDARDS CONFORMANCE

toascii(): AES, SVID2, SVID3, XPG2, XPG3, XPG4

tolower(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

toupper(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

_tolower(): AES, SVID2, SVID3, XPG2, XPG3, XPG4

_toupper(): AES, SVID2, SVID3, XPG2, XPG3, XPG4